Ion selective monoelectrode complex

ABSTRACT

An ion selective monoelectrode complex which is favorably employable to manufacture an ion activity measuring apparatus, has on a common non-electroconductive support sheet, plural ion selective monoelectrodes each of which is composed of an electrode composite consisting of, in order, a silver metal layer, a silver halide layer, an electrolytic material layer, and an ion selective membrane, and an electroconductive terminal which is electrically connected to the silver metal layer and which has an exposed surface, under the condition that the ion selective monoelectrodes are aligned, without electric contact with each other, along an imaginary line bridging the electrode composite and the electroconductive terminal.

FIELD OF THE INVENTION

[0001] The present invention relates to an ion selective monoelectrodecomplex and an ionic activity-measuring apparatus which is favorablyemployable for analysis of ionic components in liquid samples such as awhole blood sample, a serum sample, and a urine sample.

BACKGROUND OF THE INVENTION

[0002] An ionic activity-measuring apparatus utilizing an ion selectiveelectrode is widely employed for analyzing ionic components in a liquidsample such as a whole blood sample or a serum sample.

[0003] U.S. Pat. No. 4,571,293 (which corresponds to EP 0 160 997 B1)discloses an ionic activity-measuring apparatus using an ion selectiveelectrode which is illustrated in FIG. 1 of the drawings attached tothis specification.

[0004] In FIG. 1, the ionic activity-measuring apparatus comprises anon-electroconductive support 11, a pair of electrodes each of whichcomprises a silver metal layer 12 a, 12 b and a silver halide layer 13a, 13 b, a common electrolytic material layer 14, a common ion selectivemembrane 15, and a common non-electroconductive cover sheet 16 having apair of openings 17 a, 17 b for receiving and keeping a sample solutionand a reference solution, respectively, each opening being placed aboveeach electrode unit, and having thereon an a bridge member 18 forelectrically bridging the sample solution received in one opening 17 aand the reference solution received in another opening 17 b. Each of thesilver metal layer 12 a, 12 b has an exposed surface 10 a, 10 b,respectively. By placing probes of a potentiometer 19 on these exposedsilver metal surface 10 a, 10 b, the produced electric potentialdifference can be measured.

[0005]FIG. 2 illustrates an industrially employed process for preparingthe ionic activity-measuring apparatus of FIG. 1.

[0006] In industry, the ionic activity-measuring apparatus of FIG. 1 isgenerally manufactured in a mass scale, by the steps of:

[0007] (1) preparing a longitudinal sheet composed of anon-electroconductive sheet 11 and a silver metal layer 12 deposited orlaminated on the non-electroconductive sheet 11;

[0008] (2) making a linear scratch 21 on the silver metal layer 12 underthe condition that the scratch is extended in the longitudinal directionand reach the non-electro-conductive sheet 11, to divide the silvermetal layer 12 into two silver metal portions 12 a, 12 b, and coveringeach silver metal portion 12 a, 12 b on its side areas with a polymermaterial layer 20 a, 20 b, leaving uncovered area in the form of astripe (or belt) on the silver metal portion 12 a, 12 b;

[0009] (3) halogenating the silver metal portion 12 a, 12 b in theuncovered areas to form silver halide layers 13 a, 13 b, respectively,on the surface of the silver metal portion in the uncovered area;

[0010] (4) forming an electrolytic material layer 14 on the scratch andthe silver halide portions;

[0011] (5) peeling the polymer material layer 20 a, 20 b off from thesilver metal layer to produce an exposed silver metal area 10 a, 10 b,and placing an ion selective membrane 15 on an electrolytic materiallayer 14; and

[0012] (6) finally placing a non-electroconductive member 16 having twoopenings 17 a, 17 b on the ion selective membrane 15 and then placing abridge 18 on the member 16 to connect the openings 12 a, 17 b.

[0013] The above-described industrial method is advantageous formanufacturing a great number of ion selective electrodes in a massscale.

[0014] The ion selective electrode can measure an ionic activity of H⁺,Li⁺, Na⁺, K₊, Mg²⁺, Ca²⁺, Cl⁻, HCO₃ ³¹ , or CO₃ ²⁻, by employing anappropriate ion selective membrane.

[0015] U.S. Pat. No. 4,789,435 describes an ion selective electrodeassembly comprising plural ion selective electrodes for analyzing pluralionic components such as Na⁺, K⁺, and Cl⁻, simultaneously. In theassembly, one of plural ion selective electrodes has an ion selectivemembrane differing from that of other ion selective electrode inchemical composition.

SUMMARY OF THE INVENTION

[0016] It is an object of the present invention to provide an ionselective electrode having a satisfactory analytical performance at arelatively low production cost.

[0017] The object of the invention also resides in providing a method ofmanufacturing ion selective electrodes having satisfactory analyticalperformance in a mass scale at a relatively low production cost.

[0018] The present invention resides in an ion selective monoelectrodecomplex (hereinafter referred to as “Type A” complex), on a commonnon-electroconductive support sheet, plural ion selective monoelectrodeseach of which is composed of an electrode composite comprising, inorder, a silver metal layer, a silver halide layer, an electrolyticmaterial layer, and an ion selective membrane, and an electroconductiveterminal which is electrically connected to the silver metal layer andwhich has an exposed surface, under the condition that the ion selectivemonoelectrodes are aligned, without electric contact with each other,along an imaginary line bridging the electrode composite and theelectroconductive terminal

[0019] The above-mentioned ion selective electrode of Type A ispreferably manufactured in a mass scale by a process comprising thesteps of:

[0020] making two or more linear scratches on a longitudinalnon-electroconductive sheet having thereon a silver metal layer underthe condition that the scratches are extended in the longitudinaldirection and reach the non-electroconductive sheet;

[0021] covering the silver metal layer with a polymer material layer inthe form of a stripe on one side of each linear scratch, leavinguncovered area in the form of a stripe;

[0022] halogenating the silver metal layer in the uncovered area to forma silver halide layer on the surface of the silver metal layer in theuncovered area;

[0023] forming an electrolytic material layer on the polymer materiallayer and the silver halide layer;

[0024] peeling the polymer material layer off from the silver metallayer to remove the polymer material layer and the electrolytic materiallayer placed on the polymer material layer simultaneously;

[0025] placing an ion selective membrane on an electrolytic materiallayer formed on the silver halide layer;

[0026] and

[0027] cutting thus processed longitudinal sheet in the directiontraversing the longitudinal sheet to give a plurality of the ionselective monoelectrode complexes.

[0028] The ion selective electrode of Type A is also preferablymanufactured in a mass scale by a process comprising the steps of:

[0029] covering a longitudinal non-electroconductive sheet havingthereon a silver metal layer with two or more polymer material layers inthe form of a stripe in the longitudinal direction, leaving uncoveredarea in the form of a stripe;

[0030] making one or more linear scratches on the silver metal layer inthe vicinity of the polymer material layers under the condition that thescratches are extended in the longitudinal direction and reach thenon-electroconductive sheet;

[0031] halogenating the silver metal layer in the uncovered area to forma silver halide layer on the surface of the silver metal layer in theuncovered area;

[0032] forming an electrolytic material layer on the polymer materiallayer and the silver halide layer;

[0033] peeling the polymer material layer off from the silver metallayer to remove the polymer material layer and the electrolytic materiallayer placed on the polymer material layer, simultaneously;

[0034] placing an ion selective membrane on an electrolytic materiallayer formed on the silver halide layer;

[0035] and

[0036] cutting thus processed longitudinal sheet in the directiontraversing the longitudinal sheet to give a plurality of the ionselective monoelectrode complexes.

[0037] The present invention also resides in an ionic activity measuringapparatus (of Type A) comprising a pair of the ion selectivemonoelectrode complex, which are arranged in parallel without electriccontact with each other, a non-electroconductive covering element havingopenings which is placed on the ion selective membranes of the complexesto receive and keep an applied liquid sample to bring it into contactwith an ion selective membrane of each ion selective monoelectrode, andbridge elements placed on the covering element to connect one openingplaced on an ion selective membrane of one ion selective monoelectrodecomplex with other opening placed on an ion selective membrane ofanother ion selective monoelectrode complex.

[0038] The invention further resides in an ion selective monoelectrodecomplex (hereinafter referred to as “Type B” complex), having, on acommon non-electroconductive support sheet, plural ion selectivemonoelectrodes each of which is composed of an electrode compositecomprising, in order, a silver metal layer, a silver halide layer, anelectrolytic material layer, and an ion selective membrane, all silvermetal layers being electrically connected with each other, and anelectroconductive terminal which is electrically connected to one of thesilver metal layers and which has an exposed surface, under thecondition that the ion selective monoelectrodes are aligned along animaginary line bridging the electrode composite and theelectroconductive terminal.

[0039] The above-mentioned ion selective electrode (of Type B) of theinvention is preferably manufactured in a mass scale by a processcomprising the steps of:

[0040] covering a silver metal layer placed on a longitudinalnon-electroconductive sheet with a polymer material layer in the form ofa stripe on a side of the sheet, leaving uncovered area in the form of astripe;

[0041] halogenating the silver metal layer in the uncovered area to forma silver halide layer on the surface of the silver metal layer in theuncovered area;

[0042] forming an electrolytic material layer on the polymer materiallayer and the silver halide layer;

[0043] peeling the polymer material layer off from the silver metallayer to remove the polymer material layer and the electrolytic materiallayer placed on the polymer material layer, simultaneously;

[0044] placing an ion selective membrane on an electrolytic materiallayer formed on the silver halide layer;

[0045] and

[0046] cutting thus processed longitudinal sheet in the directiontraversing the longitudinal sheet to give a plurality of the ionselective monoelectrode complexes.

[0047] The invention furthermore resides in an ionic activity measuringapparatus (of Type B) comprising a pair of the ion selectivemonoelectrode complex, which are arranged in parallel without electriccontact with each other, a non-electroconductive covering element havingopenings which is placed on the ion selective membranes of the complexesto receive and keep an applied liquid sample to bring it into contactwith an ion selective membrane of each ion selective monoelectrode, andbridge elements placed on the covering element to connect one openingplaced on an ion selective membrane of one ion selective monoelectrodecomplex with other opening placed on an ion selective membrane ofanother ion selective monoelectrode complex.

BRIEF DESCRIPTION OF DRAWINGS

[0048]FIG. 1 illustrates a representative structure of a conventionalionic activity-measuring apparatus.

[0049]FIG. 2 illustrates a representative process for the preparation ofthe ionic activity-measuring apparatus of FIG. 1.

[0050]FIG. 3 illustrates a representative structure of an ionicactivity-measuring apparatus (of Type A) according to the invention.

[0051]FIG. 4 illustrates a representative process for preparing an ionselective monoelectrode complex (of Type A) of the invention.

[0052]FIG. 5 illustrates an example of possible arrangement of two ionselective monoelectrode complexes for manufacturing an ionicactivity-measuring apparatus (of Type A) of the invention.

[0053]FIG. 6 illustrates another example of possible arrangement of twoion selective monoelectrode complexes for manufacturing an ionicactivity-measuring apparatus (of Type A) of the invention.

[0054]FIG. 7 illustrates a representative structure of an ionicactivity-measuring apparatus (of Type B) according to the invention.

[0055]FIG. 8 illustrates a representative process for preparing an ionselective monoelectrode complex (of Type B) of the invention.

[0056]FIG. 9 illustrates an example of possible arrangement of two ionselective monoelectrode complexes for manufacturing an ionicactivity-measuring apparatus (of Type B) of the invention.

[0057]FIG. 10 illustrates another example of possible arrangement of twoion selective monoelectrode complexes for manufacturing an ionicactivity-measuring apparatus (of Type B) of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0058] The present invention is further described by referring to thefigures illustrated in the attached drawings. The ion selectivemonoelectrode complex of the invention and the ionic activity-measuringapparatus of the invention is classified into two types, that is, Type Aand Type B. Both monoelectrode complexes and apparatuses are describedbelow in order.

[0059] [Type A]

[0060]FIG. 3 illustrates a representative structure of an ionicactivity-measuring apparatus (of Type A) according to the invention.

[0061] The ionic activity-measuring apparatus of FIG. 3 can measurethree different ionic species such as sodium ion (Na⁺), potassium ion(K⁺), and chloride ion (Cl⁻), almost simultaneously.

[0062] The ionic activity-measuring apparatus of Type A in FIG. 3 iscomposed of an ion selective monoelectrode complex of Type A which has,on a common non-electroconductive support sheet 111, three ion selectivemono-electrodes (for the measurements of Na⁺, K⁺, and Cl⁻), each ofwhich is composed of an electrode composite comprising, in order, asilver metal layer 112 a, 112 b, 112 c, a silver halide layer 113 a, 113b, 113 c, an electrolytic material layer 114 a, 114 b, 114 c, and an ionselective membrane 115 a, 115 b, 115 c, and an electroconductiveterminal having an exposed surface 110 a, 110 b, 110 c, which iselectrically connected to the silver metal layer 112 a, 112 b, 112 c,respectively. The materials of the ion selective membranes 115 a, 115 b,115 c are different from each other so that a sodium ion selectivemonoelectrode, a potassium ion selective monoelectrode, and a chlorideion selective monoelectrode can be produced.

[0063] The ion selective monoelectrodes are aligned, with-out electriccontact with each other by the scratch formed on thenon-electroconductive support sheet 111, along an imaginary linebridging the electrode composite and the electroconductive terminal,that is, the alignment of terminal 110 a—silver metal layer 112a—terminal 110 b—silver metal layer 112 b—terminal 110 c—silver metallayer 112 c. In the scratches, an electrolytic material extending fromthe adjacent electrolytic material layer is embedded.

[0064] The ionic activity-measuring apparatus is composed of a pair ofthe ion selective Tonoelectrode complex which are arranged in parallel.

[0065] On each of a pair of the sodium ion selective monoelectrodes, apair of the potassium ion selective monoelectrodes, and a pair of thechloride ion selective monoelectrodes are placed a non-electroconductiveplate unit 116 a, 116 b, 116 c having a pair of openings 117 a, 117 b,117 c for receiving and holding a sample solution and a referencesolution. In FIG. 3, three non-electroconductive plate units arecombined to produce one plate.

[0066] On the non-electroconductive plate unit 116 a, 116 b, 116 c areplaced a bridge member 118 a, 118 b, 118 c, which can bridgeelectrically a sample solution received in one opening and a referencesolution received in another opening.

[0067] Thus, an ionic activity-measuring apparatus of Type A which is ameasuring apparatus assembly for measuring sodium ion, potassium ion,and chloride ion, at the same time or different times. In themeasurement, an electric conductive probes of a potentiometer 119 a, 119b, 119 c are brought into contact with the electroconductive terminal110 a, 110 b, 110 c of the apparatus, and an electric potentialdifference produced in a measuring apparatus unit which has received asample solution and a reference solution is measured.

[0068] Thus, the ionic activity-measuring apparatus of the invention ischaracteristic in assembling a pair of ion selective monoelectrodecomplexes, which is in contrast to the known multiple ionicactivity-measuring apparatus which is manufactured by assembling two ormore ion selective electrode units having a specific ion selectivemembrane.

[0069]FIG. 4 illustrates a representative process for the preparation ofa large number of ion selective monoelectrode complexes of Type A, suchas those utilized for manufacturing the ionic activity-measuringapparatus of FIG. 3.

[0070] The process comprises the following steps:

[0071] (1) preparing a longitudinal (or continuous)non-electroconductive sheet 111 having a silver metal layer 112 on itssurface;

[0072] (2) producing two linear scratches 121 a, 121 b on the silvermetal layer 112, under the condition that the scratches 121 a, 121 b areextended in the longitudinal direction and reach the surface of thenon-electroconductive sheet 111 to divide the silver metal layer 112into three silver metal layers 112 a, 112 b, 112 c, and covering each ofthe divided silver metal layers 112 a, 112 b, 112 c with a polymermaterial layer in the form of a stripe 120 a, 120 b, 120 c, on one sideof each linear scratch and on the side of the non-electroconductivesheet 111, leaving uncovered area in the form of a stripe;

[0073] (3) halogenating the silver metal layer 112a, 112 b, 112 c in theuncovered area to form a silver halide layer 113 a, 113 b, 113 c on thesurface of the silver metal layer in the uncovered area;

[0074] (4) forming an electrolytic material layer 114 on the polymermaterial layer 120 a, 120 b, 120 c and the silver halide layer 113 a,113 b, 113 c;

[0075] (5) peeling the polymer material layer 120 a, 120 b, 120 c offfrom the silver metal layer to remove the polymer material layer and theelectrolytic material layer placed on the polymer material layersimultaneously, to divide the electrolytic material layer to threeelectrolytic material layers 114 a, 114 b, 114 c and produce exposedareas 110 a, 110 b, 110 c on the silver metal layers 112 a, 112 b, 112c;

[0076] (6) placing an ion selective membrane 115 a, 115 b, 115 c on theelectrolytic material layer 114 a, 114 b, 114 c;

[0077] and

[0078] (7) cutting thus processed longitudinal sheet in the directiontraversing the longitudinal sheet to give a plurality of the ionselective monoelectrode complexes having the illustrated pattern (planeview).

[0079] The halogenation of the silver metal layer in the step (3) can becarried out in the known manner such as that employing an aqueousdichromate solution or an aqueous PDTA•Fe(III) solution. Otherwise, adispersion containing silver halide particles and a binder can be coatedon the silver metal layer and dried to form a silver halide layer. Inthe step (4), the electrolytic material layer can be independentlyformed on each silver halide layer, so that an electrolytic materialsuitable for each ion selective membrane to be coated on theelectrolytic material layer can be selected.

[0080] For the producing the ion selective monoelectrode complex andmanufacturing the ionic activity-measuring apparatus, a variety of knownmaterials and technologies can be adopted. Examples of these knownmaterials and technologies are described in U.S. Pat. No. 4,053,381, No.4,171,246, and No. 4,214,968, and Research Disclosure No. 16113(September, 1977).

[0081]FIG. 5 is a plane view of the arrangement of the ionicactivity-measuring apparatus of FIG. 3.

[0082] Alternatively, a pair of the ion selective monoelectrodecomplexes can be arranged in the manner illustrated in FIG. 6.

[0083] [Type B]

[0084]FIG. 7 illustrates a representative structure of an ionicactivity-measuring apparatus (of Type B) according to the invention.

[0085] The ionic activity-measuring apparatus of FIG. 7 can measurethree different ionic species such as sodium ion (Na⁺), potassium ion(K⁺), and chloride ion (Cl⁻), almost simultaneously.

[0086] The ionic activity-measuring apparatus of Type B in FIG. 7 iscomposed of an ion selective monoelectrode complex of Type B which has,on a common non-electroconductive support sheet 211, three ion selectivemonoelectrodes electrodes (for the measurements of Na⁺, K⁺, and Cl⁻),each of which is composed of an electrode composite comprising, inorder, a common silver metal layer 212, a common silver halide layer213, a common electrolytic material layer 214, and an ion selectivemembrane 215 a, 215 b, 215 c, and an electroconductive terminal havingan exposed surface 210, which is electrically connected to the silvermetal layer 212. The materials of the ion selective membranes 215 a, 215b, 215 c are different from each other so that a sodium ion selectivemonoelectrode, a potassium ion selective monoelectrode, and a chlorideion selective monoelectrode can be produced.

[0087] The ion selective monoelectrodes are aligned along an imaginaryline bridging the electrode composite and the electroconductiveterminal, that is, the alignment of terminal 210—ion selective membrane215 a—ion selective membrane 215 b—ion selective membrane 215 c.

[0088] The ionic activity-measuring apparatus is composed of a pair ofthe ion selective monoelectrode complex which are arranged in parallel.

[0089] On each of a pair of the sodium ion selective monoelectrodes, apair of the potassium ion selective monoelectrodes, and a pair of thechloride ion selective monoelectrodes are placed a non-electroconductiveplate 216 having three pairs of openings 217 a, 217 b, 217 c forreceiving and holding a sample solution and a reference solution. On thenon-electroconductive plate unit 216 a, 216 b, 216 c are placed a bridgemember 218 a, 218 b, 218 c, which can bridge electrically a samplesolution received in one opening and a reference solution received inanother opening.

[0090] Thus, an ionic activity-measuring apparatus of Type B which is ameasuring apparatus assembly for measuring sodium ion, potassium ion, orchloride ion. In the measurement, an electric conductive probes of apotentiometer 219 is brought into contact with the electroconductiveterminal 210 of the apparatus, and an electric potential differenceproduced in a measuring apparatus unit which has received a samplesolution and a reference solution is measured.

[0091]FIG. 8 illustrates a representative process for the preparation ofa large number of ion selective monoelectrode complexes of Type B, suchas those utilized for manufacturing the ionic activity-measuringapparatus of FIG. 7.

[0092] The process comprises the following steps:

[0093] (1) preparing a longitudinal (or continuous)non-electroconductive sheet 211 having a silver metal layer 212 on itssurface;

[0094] (2) covering a silver metal layer 212 with a polymer materiallayer 220 in the form of a stripe on a side of the sheet, leavinguncovered area in the form of a stripe;

[0095] (3) halogenating the surface of the silver metal layer 212 in theuncovered area to form a silver halide layer 213 on the surface of thesilver metal layer 212 in the uncovered area;

[0096] (4) forming an electrolytic material layer 214 on the polymermaterial layer 220 and the silver halide layer 213;

[0097] (5) peeling the polymer material layer 220 off from the silvermetal layer 212 to remove the polymer material layer 220 and theelectrolytic material layer placed on the polymer material layer,simultaneously;

[0098] (6) placing three ion selective membranes 215 a, 215 b, 215 c onthe electrolytic material layer 214;

[0099] and

[0100] (7) cutting thus processed longitudinal sheet in the directiontraversing the longitudinal sheet to give a plurality of the ionselective monoelectrode complexes having the illustrated pattern (planeview).

[0101]FIG. 9 is a plane view of the arrangement of the ionicactivity-measuring apparatus of FIG. 7.

[0102] Alternatively, a pair of the ion selective monoelectrodecomplexes can be arranged in the manner illustrated in FIG. 10.

[0103] The ion selective monoelectrode complexes of Type A or Type B canbe placed inversely and assembled to constitute an ionicactivity-measuring apparatus illustrated in U.S. Pat. No. 4,789,435.

[0104] The present invention is further described in the followingexamples.

EXAMPLE 1

[0105] On a longitudinal polyethylene terephthalate film (support,thickness 180 μm, length 300 m, width 1300 mm) was deposited a silvermetal layer (thickness approx. 8,000 angstroms) by continuous vacuumdeposition. The film was slitted in the longitudinal direction to give acontinuous silver metal-coated strip having a width of 24 mm.

[0106] On the silver metal layer were placed three film forming polymermaterial layers (thickness: 30 μm, produced using vinyl chloride-vinylacetate copolymer in a mixture of toluene and methyl ethyl ketone) inthe form of stripes (width: 4 mm, space between the stripes: 4 mm). Ascratch or groove (depth of 70 μm) was produced on the silver metallayer and support on the left side of each polymer material layer, togive three divided silver metal layers.

[0107] Thus treated longitudinal film was then placed in an aqueousoxidation-halogenation processing solution containing 60 mM ofhydrochloric acid and 12 mM of potassium dichromate for 90 seconds, forperforming catalytic oxidation-chlorination processing. The processedfilm was recovered, washed with water, and dried to give a film havingon its surface plural Ag/AgCl electrode composites.

[0108] A solution of electrolytic material was prepared by dissolving2.975 g of sodium chloride in 42.5 g of an aqueous organic solventmixture of 2.5 g of acetone, 20 g of ethanol, and 20 g of water. Thesolution was then coated on the Ag/AgCl electrode composites and driedto give an electrolytic material layer in an amount of 2.2 g/m².

[0109] The polymer films were peeled off from the silver metal layer, toremove simultaneously the electrolytic material placed on the polymerfilms. Thus portions of the silver metal layer were exposed.

[0110] Separately, the following three coating solutions of ionselective membrane materials were prepared: (1) Composition of sodiumion selective membrane- forming solution Vinyl chloride-vinyl acetatecopolymer 0.9 g (VYNS, available from Union carbide) Phenyl dicresylphosphate 1.2 g Methylmonensin 0.1 g Sodium tetraphenylborate 2 mgMethyl ethyl ketone

[0111] (2) Composition of potassium ion selective mem- brane-formingsolution VYNS 0.9 g Dioctyl adipate 1.2 g Valinomycin 44 mg Potassiumtetrakis-p-chlorophenylborate 18 mg Methyl ethyl ketone 5 g 1% SH510(polysiloxane in methyl ethyl ketone) 50 mg

[0112] (3) Composition of chloride ion selective membrane- formingsolution VYNS  0.9 g Capricoat  1.3 g Didodecyl phthalate 0.05 gAmmonium trioctylpropylchloride 0.05 g

[0113] Each of the compositions were continuously spread on eachelectrolytic material layer sin the form of stripe of the longitudinalfilm moving at a rate of 15 m/min., to give three stripes of ionselective layer (width 4 mm).

[0114] The longitudinal film was cut in the width direction at adistance of 4 mm to give plural ion selective monoelectrode complexes(24 mm×4 mm).

[0115] A pair of thus produced ion selective monoelectrode complexeswere assembled to constitute an ionic activity-measuring apparatus forthe ionic analysis of Na, K and Cl, in the form illustrated in FIG. 3.

1. An ion selective monoelectrode complex having, on a commonnon-electroconductive support sheet, plural ion selective monoelectrodeseach of which is composed of an electrode composite comprising, inorder, a silver metal layer, a silver halide layer, an electrolyticmaterial layer, and an ion selective membrane, and an electroconductiveterminal which is electrically connected to the silver metal layer andwhich has an exposed surface, under the condition that the ion selectivemonoelectrodes are aligned, without electric contact with each other,along an imaginary line bridging the electrode composite and theelectroconductive terminal.
 2. The ion selective monoelectrode complexof claim 1, wherein one ion selective monoelectrode has an ion selectivemembrane which is responsive to one ionic species, while other one ormore ion selective monoelectrodes have an ion selective membrane whichis responsive to other ionic species.
 3. The ion selective monoelectrodecomplex of claim 1, which comprises three or more ion selectivemonoelectrodes that are aligned without electric contact with eachother, along an imaginary line bridging the electrode composite and theelectroconductive terminal.
 4. The ion selective monoelectrode complexof claim 1, wherein the ion selective moncelectrodes are insulated fromeach other with an electrolytic material extending from the electrolyticmaterial layer of the monoelectrode on one side.
 5. (cancel)
 6. (cancel)7. An ionic activity measuring apparatus comprising a pair of ionselective monoelectrode complex of claim 1, which are arranged inparallel without electric contact with each other, anon-eleetroconductive covering element having openings which is placedon the ion selective membranes of the complexes to receive and keep anapplied liquid sample to bring it into contact with an ion selectivemembrane of each ion selective monoelectrode, and bridge elements placedon the covering element to connect one opening placed on an ionselective membrane of one ion selective monoelectrode complex with otheropening placed on an ion selective membrane of another ion selectivemonoelectrode complex.
 8. An ion selective monoelectrode complex having,on a common non-electroconductive support sheet, plural ion selectivemonoelectrodes each of which is composed of an electrode compositecomprising, in order, a silver metal layer, a silver halide layer, anelectrolytic material layer, and an ion selective membrane, all silvermetal layers being electrically connected with each other, and anelectroconductive terminal which is electrically connected to one of thesilver metal layers and which has an exposed surface, under thecondition that the ion selective monoelectrodes are aligned alone animaginary line bridging the electrode composite and theelectroconductive terminal.
 9. The ion selective monoelectrode complexof claim 8, wherein one ion selective monoelectrode has an ion selectivemembrane which is responsive to one ionic species, while other one ormore ion selective momelectrodes have an ion selective membrane which isresponsive to other ionic species.
 10. The ion selective monoelectrodecomplex of claim 8, in which the electroconductive terminal is placed onone end of the monoelectrode complex.
 11. (cancel)
 12. An ionic activitymeasuring apparatus comprising a pair of ion selective monoelectrodecomplex of claim 8, which are arranged in parallel without electriccontact with each other, a non-electroconductive covering element havingopenings which is placed on the ion selective membranes oξ the complexesto receive and keep an applied liquid sample to bring it into contactwith an ion selective membrane of each ion selective monoelectrode, andbridge elements placed on the covering element to connect one openingplaced on an ion selective membrane of one ion selective monoelectrodecomplex with other opening placed on an ion selective membrane ofanother ion selective monoelectrode complex.